1. Field of the Invention
The present invention relates to a substrate processing apparatus for and a substrate processing method of supplying a processing liquid to surface peripheral sections of substrates, such as semiconductor wafers, glass substrates for photomask, glass substrates for liquid crystal display, substrates for plasma display, substrates for FED (field emission display), substrates for optical disk, substrates for magnetic disk and substrates for magnet-optical disk, to thereby perform a surface treatment of the surface peripheral sections of the substrates.
2. Description of the Related Art
In a manufacturing process which is a series of treatments of substrates such as semiconductor wafers, film deposition steps are executed to form various types of thin films on the front surfaces of the substrates. Film deposition steps sometimes result in films on the back surfaces of the substrates or peripheral sections in the front surfaces of the substrates. However, it is generally circuit forming areas alone at the center of the front surfaces of the substrates that need film deposition on the substrates, and film deposition if any on the back surfaces of the substrates or in the peripheral sections of the front surfaces of the substrates may give rise to the following problem. That is, a thin film formed in a peripheral section of the front surface of a substrate may get stripped off due to its contact with other apparatus at a later step following a film deposition step. A thin film thus stripped off may adhere to a circuit forming area at the center of the front surface of the substrate or to a substrate processing apparatus, leading to a lowered yield for manufacturing of products or a trouble with the substrate processing apparatus itself.
For removal of a thin film formed on the back surface of a substrate or in a peripheral section of the front surface of the substrate therefore, the apparatus according to JP-A-2006-41444 has been proposed for instance. In this apparatus, a support part is disposed projecting toward above from a spin base such that it supports a substrate while abutting on a peripheral section of the back surface of the substrate, and the support part horizontally holds the substrate whose front surface is directed toward above and on the front surface of which a thin film is formed. From an atmosphere blocking plate (which corresponds to the “opposed member” of the invention) disposed above the substrate, inert gas is fed to a space which is defined between the substrate and the atmosphere blocking plate, whereby the substrate is pressed against the support part and rotated while held at the spin base. Further, with a nozzle inserted in a nozzle insertion hole which is bored in a peripheral section of the atmosphere blocking plate, a chemical solution is supplied as a processing liquid from the nozzle toward the peripheral section of the front surface of the substrate which is rotating. As a result, the unwanted substance adhering to the peripheral section of the front surface of the substrate is etched and removed. In addition, a chemical solution is supplied as a processing liquid toward the back surface of the substrate which is rotating. The chemical solution spreads all over the back surface of the substrate, whereby the unwanted substance adhering to the back surface of the substrate is etched and removed. In this manner, the thin film is etched and removed only on the back surface of the substrate and in the peripheral section of the front surface of the substrate.
A manufacturing process of an electronic component such as a semiconductor device and a liquid crystal display device includes a process to form fine patterns by performing processes such as film deposition and etching on a substrate surface. It is necessary to keep the substrate surface clean in order to perform fine processing favorably. Hence, a cleaning process is performed to the substrate surface as needed. Consequently, a cleaning liquid is supplied to the substrate and ultrasonic vibration is provided to the cleaning liquid to remove particles adhering to the substrate. In this way, the particles are effectively separated and removed from the substrate by the ultrasonic vibrating energy which the cleaning liquid has.
As such a substrate cleaning apparatus, the following systems have been proposed. For example, an apparatus disclosed in JP-A-11-244796 cleans the substrate surface by discharging a cleaning liquid, to which the ultrasonic vibration is provided, from a nozzle toward the substrate surface. Further, apparatuses disclosed in Japanese Patent No. 3493492 and JP-A-2001-87725 form a liquid film of the cleaning liquid on the substrate surface and the ultrasonic vibration is provided to the liquid film to clean the substrate surface. Furthermore, in an apparatus disclosed in JP-A-2006-326486, an ultrasonic transducer is disposed facing the substrate surface and a cleaning liquid flows in the gap therebetween to clean the substrate surface.